9231/32 · Oct/Nov 2024
Download PDFA particle of mass is attached to one end of a light elastic string of natural length and modulus of elasticity . The other end of the string is attached to a fixed point on a smooth horizontal surface. The particle is moving in a horizontal circle about with the string taut and with constant angular speed . Find the extension of the string.
A particle of mass is attached to one end of a light elastic spring of natural length and modulus of elasticity . The other end of the spring is attached to a fixed point . The spring hangs vertically with below . The particle is pulled down vertically and released from rest when the length of the spring is . Find the distance of below when first comes to instantaneous rest.
The diagram shows two identical smooth uniform spheres and of equal radii and each of mass . The two spheres are moving on a smooth horizontal surface when they collide with speeds and respectively. Immediately before the collision, ’s direction of motion makes an angle with the line of centres and ’s direction of motion is perpendicular to that of . After the collision, moves perpendicular to the line of centres. The coefficient of restitution between the spheres is .


Find the value of .
Find the total loss of kinetic energy as a result of the collision.
Find, in degrees, the angle through which the direction of motion of is deflected as a result of the collision.
The end of a uniform rod of length and weight is in contact with a rough vertical wall. One end of a light inextensible string of length is attached to the midpoint of the rod. The other end of the string is attached to a point on the wall, vertically above . The rod is in equilibrium when the angle between the rod and the wall is , where . A particle of weight is attached to the point on the rod, where the distance is equal to () (see diagram). The rod and the string are in a vertical plane perpendicular to the wall. The coefficient of friction between the rod and the wall is . The rod is about to slip down the wall.

Find the value of .
Find, in terms of , the magnitude of the frictional force between the rod and the wall.
A particle is projected from a point on horizontal ground with speed at an angle above the horizontal, where . The particle moves freely under gravity and passes through the point with coordinates relative to horizontal and vertical axes through in the plane of the motion.
Use the equation of the trajectory to show that .
At the instant when is moving horizontally, a particle is projected from with speed at an angle above the horizontal. The particles and reach the ground at the same point and at the same time. Express in the form , where is a rational number.
A particle of mass is attached to one end of a light inextensible string of length . The other end of the string is attached to a fixed point . The particle is held with the string taut and the string makes an angle with the downward vertical through . The particle is projected at right angles to the string with speed and begins to move downwards along a circular path. When the string is vertical, it strikes a small smooth peg at the point which is vertically below . The circular path and the point are in the same vertical plane. After the string strikes the peg, the particle begins to move in a vertical circle with centre . When the string makes an angle with the upward vertical through the string becomes slack (see diagram). The distance of below is .

Find the value of .
Find the ratio of the tensions in the string immediately before and immediately after it strikes the peg.
A particle of mass is held at rest at a point and released so that it moves vertically under gravity against a resistive force of magnitude , where is the velocity of at time .
Find an expression for in terms of .
The displacement of from at time is . Find an expression for in terms of .






